Twernmilt

Perhaps someone can help me diagnose my croissants. This is the texture I'm aiming for: This is the texture I achieved: I'm using the recipe from Tartine, which has worked wonderfully for me in the past, but now I'm struggling to get a good batch. This batch was far too dense and somewhat spongy. My first thought is that I didn't let them proof long enough. It's fairly warm in my apartment, so I let them proof for two hours which is the lower end of what the recipe calls for. A possible related question: What should the texture of the dough be just before it's rolled out for the first time? My dough was quite stiff. I added a few tablespoons of milk to loosen it, but it was still very firm and I had to struggle with it a bit to roll it out for each fold.